Weird pop-in like things going on.

I recently did a map that is 2fort with the hightower in the center, unfortunately the current version has a bug where when ever you go into REDs base certain areas will disappear and re appear for no apparent reason.
It not small either, you could walk into a room and it will vanish until you start walking further foward.

The only way I can think to fix this is by removing some triggers in the map, but I think that would cause some performance issues. If its the only solution, then alert me.

FindPortalSide: Couldn't find a good match for which brush to assign to a portal near (2048.0 4184.0 -420.0)
Leaf 0 contents: CONTENTS_SOLID
Leaf 1 contents:
viscontents (node 0 contents ^ node 1 contents): CONTENTS_SOLID
This means that none of the brushes in leaf 0 or 1 that touches the portal has CONTENTS_SOLID
Check for a huge brush enclosing the coordinates above that has contents CONTENTS_SOLID
Candidate brush IDs:

FindPortalSide: Couldn't find a good match for which brush to assign to a portal near (2048.0 4184.0 840.0)
Leaf 0 contents: CONTENTS_SOLID
Leaf 1 contents:
viscontents (node 0 contents ^ node 1 contents): CONTENTS_SOLID
This means that none of the brushes in leaf 0 or 1 that touches the portal has CONTENTS_SOLID
Check for a huge brush enclosing the coordinates above that has contents CONTENTS_SOLID
Candidate brush IDs:

FindPortalSide: Couldn't find a good match for which brush to assign to a portal near (2048.0 4696.0 -420.0)
Leaf 0 contents: CONTENTS_SOLID
Leaf 1 contents:
viscontents (node 0 contents ^ node 1 contents): CONTENTS_SOLID
This means that none of the brushes in leaf 0 or 1 that touches the portal has CONTENTS_SOLID
Check for a huge brush enclosing the coordinates above that has contents CONTENTS_SOLID
Candidate brush IDs:

FindPortalSide: Couldn't find a good match for which brush to assign to a portal near (2048.0 4696.0 840.0)
Leaf 0 contents: CONTENTS_SOLID
Leaf 1 contents:
viscontents (node 0 contents ^ node 1 contents): CONTENTS_SOLID
This means that none of the brushes in leaf 0 or 1 that touches the portal has CONTENTS_SOLID
Check for a huge brush enclosing the coordinates above that has contents CONTENTS_SOLID
Candidate brush IDs:

FindPortalSide: Couldn't find a good match for which brush to assign to a portal near (2560.0 5120.0 612.0)
Leaf 0 contents:
Leaf 1 contents: CONTENTS_SOLID
viscontents (node 0 contents ^ node 1 contents): CONTENTS_SOLID
This means that none of the brushes in leaf 0 or 1 that touches the portal has CONTENTS_SOLID
Check for a huge brush enclosing the coordinates above that has contents CONTENTS_SOLID
Candidate brush IDs:

FindPortalSide: Couldn't find a good match for which brush to assign to a portal near (3072.0 4608.0 612.0)
Leaf 0 contents:
Leaf 1 contents: CONTENTS_SOLID
viscontents (node 0 contents ^ node 1 contents): CONTENTS_SOLID
This means that none of the brushes in leaf 0 or 1 that touches the portal has CONTENTS_SOLID
Check for a huge brush enclosing the coordinates above that has contents CONTENTS_SOLID
Candidate brush IDs:

FindPortalSide: Couldn't find a good match for which brush to assign to a portal near (2336.0 3072.0 -220.0)
Leaf 0 contents: CONTENTS_SOLID
Leaf 1 contents:
viscontents (node 0 contents ^ node 1 contents): CONTENTS_SOLID
This means that none of the brushes in leaf 0 or 1 that touches the portal has CONTENTS_SOLID
Check for a huge brush enclosing the coordinates above that has contents CONTENTS_SOLID
Candidate brush IDs: